Direct memory access (DMA) is a method in which data is directly transferred between a memory and another device (for example, a peripheral equipment or the like) without going through a central processing unit (CPU). For example, a document describes that data is directly transferred from a cache memory to another cache memory in an information processing device. Another document describes that data is directly transferred from a transfer source area to a transfer destination area in a DMA transfer device.
DMA is a method for data transfer in a single node. On the other hand, a method in which data is directly transferred from a maim memory of a node to a main memory of another node is called remote direct memory access (RDMA).
Data that is transferred by RDMA is written in a main memory of a node that has received the data. In a case where a CPU of the node that has received data uses the data that has been written in the main memory, if there is no data in a cache memory, a cache miss occurs. Due to the occurrence of a cache miss, a time which it takes for the CPU to start processing of the data is increased. In view of this phenomenon, it is desirable to reduce the occurrence of a cache miss at the time of reference to the data that has been transferred by RDMA. For example, Japanese Laid-open Patent Publication No. 8-328995, Japanese Laid-open Patent Publication No. 2009-211248, or the like discusses related art.